Colossus

I believe there is a cooling fan on the back of the unit, it might have failed.

The idle will go up to about that when your truck is trying to do a Diesel Particulate Filter (DPF) regeneration cycle. Get it out on the highway and drive it for 20 miles or so at highway speeds and the regen will complete and RPMs drop back to 600. Read up more about it in your engine section of your owners manual. Best to do regens at highway speeds. They run automatically and you can't control when it goes into or out of regen, gotta let it do its thing. It will only regen over certain speeds (45+ I believe)

that's about once a year. pretty good rule of thumb.

not that I am aware of..

EXACTLY.

haven't seen any reports of leaking power steering yet. Interesting.

Same thing on my 13 Impala. Pretty typical now a days that batteries in modern vehicles only make it 3-4 years. Regardless of the brand.

I always jump the primary.

I may be way off track here but, any possibility of this being carbon build up?

Understood. How has your 03 D-Max held up? My 08 is in the body shop having some rust issues taken care of and I'm considering getting rid of her and going for a 18/19 DMAX, or a 15-19 Silverado/Sierra 6.2, or a a Dodge 2500/3500 Cummins. We'll see.

I miss the beautiful colors of the Utah high country. Grew up there for a few years. (Farmington & Ogden Valley) Now in Colorado. Great photos, Danielle.

If your truck sits for longer than 3-4 days at your place, I would recommend getting a battery tender, it will help extend the life of the battery.

You won't see 25 MPG in an HD Duramax. 19-22 MPG is more realistic for highway at 65 or under.

Put a coat of wax on the old 97 Lumina beater. Most of it still shines up nicely.

Dang, that's the best looking 2020 I've seen yet, and I hate how the 2020s look. Not bad! I'm impressed.

I try

I'm a firm believer in flushing as long as the transmission fluid is not burnt. When flushed PROPERLY it is SAFE and works. VERY well. My shop uses this. As do many other shops. FYI BG invented this safe method. No over pressurizing of the system. no damage. Watch: Older machine, but same idea. The vehicle's tranny pump does most of the work, pumping in new while pumping out the old. No over-pressurizing. Why I like flushing vs drain and fill? Flushing gets 99% of the old stuff out where as drain and fill just keeps contaminating old with new. What a waste. Only time I would do drain and fill is if the tranny has been abused and the fluid smells burnt. But an abused tranny with burnt fluid is going to be on the verge of failure as-is so what does it hurt to flush i sometimes wonder. Also, most vehicles now use screens instead of filters. The flush method cleans the screen in the process, so no need to replace the screen.

Yes there are.

go over to https://elightbars.org/forums/ they might be able to help you. Emergency equipment outfitters over there.

Opti-Lube https://www.amazon.com/Opti-Lube-Seasons-Diesel-Fuel-Additive/dp/B00FOSSQJU

You mean the fish gills?

It's a great truck, it's just not as perfect as a few on here make it out to be. It has it's own issues like all trucks do. Go visit the forums and you'll see the patterns over there just like we have patterns here with the GM trucks. Thing is- I'd probably buy a new Tundra over a new Silverado/Sierrra on the looks alone, I can't stand the new GM twins.

Wow, how sad. You have no ability to go do your own research. Grow a set, please.

BULL CRAP.

Got news for ya, it aint just a GM thing. ALL the other manufacturers are having issues trying to one up each other or keep up with each other when it comes to tech. They all have shitty ratings when it comes to computer controlled stuff.